Stoker construction



Original Filed April 5, 192% 2 Sheets-Sheet 1 June 5, 1934. w. T. HANNA1,961,215

STOKE-R CONSTRUCTION Original Filed April 5, 1929 2 Sheets-Sheet 2 Q BMQM M A TTORNE rs Patented June 5, 1934 UNITED STATES PATENT OFFICERenewed J lily 8,

4 Claims.

This invention relates to stokers in general but more particularly tostokers for use on locomotives and the like.

One of the objects of the invention is to provide a simple, compact andsturdy stoker mechanism which will effectively convey the fuel from thecoal hopper in the tender to the fire box of the locomotive andadvantageously distribute it therein.

Another object is to provide a simple and effective means for crushingabnormally large lumps of fuel within the stoker mechanism.

Another object is to provide a crushing device of the character abovedescribed which operates smoothly, and with a minimum amount of power.

Another object is to provide a crushing device of the character abovedescribed which is uniform in operation and in which excessive pressuresdo not build up.

Another object is to provide a crushing device of the characterdescribed which is durable, inexpensive, simple and economical tomanufacture. Other objects will be in part obvious and 'in part pointedout hereinafter.

The invention accordingly consists in the features of construction,combination of elements and arrangements of parts which will beexemplified in the mechanism hereinafter described and the scope of theapplication of which will be indicated in the following claims.

In the accompanying drawings is shown one of the various possibleembodiments of the invention in which:

Fig. 1 is a side elevation partially in section of a stoker mechanismembodying my invention.

Fig. 2 is an enlarged plan view of a portion of the tender hopper shownin Figure 1 with a transfer conveyer therein.

Fig. 3 is a vertical section taken on line 3--3f of Figure 2.

Figs. 4 and 5 are sectional views on the lines 4--4 and 55 respectivelyof Fig. 3.

As conductive to a more intelligent understanding of certain of thefeatures of this invention, it is pointed out that crushing structuresof the type wherein the material to be crushed is moved against and pastcrushing plates by screw conveyers have many serious disadvantages. Forexample, oftentimes, the material being'crushed becomes clogged in theregion of the crushing plates, and in the event of such a clogging in acrushing structure located in a fuel conveyer for a fuel stoker, thefuel supply to the stoker is, of course, cut off. It has been customaryto remedy or remove such clogging by (CI. 83-52) E reversing the screwconveying mechanism and in this way clear the crusher and'relieve theexcessive pressure. Such operation, however, requires a resetting of thethrottle for the stoker engine and in general causes trouble and loss oftime. Further, clogging of. this nature in a crushing device results inthe creation of excessive pressures on the crushing structure andsubjects the stoker engine and screw conveyer to undue v strain. Theseexcessive pressures strain and/or break crushing plates and other partsof the stoker mechanism and materially shorten the life of the stoker.Itis another object of this invention to overcome such dimculties asthose described above, as well as many others, in a to thoroughlypractical, dependable and economical manner.

Referring more particularly to Figure 1, 10 represents the back head ofa locomotive fire box having the usual grate bars 11 and firing opening12. Embracing this opening and rigidly mounted on the outer face of theback head is a fuel supply housing 13 which carries, at its lower end,an extension 14. This extension encompasses the delivery end of atransfer conveyer 15 (shown in dotted lines) which is rotativelysupported ina cylindrical conduit 16. The forward end of the conduit 16is provided with a universal connection with the extension 14 below adeck 17 of the locomotive. The extension 14 feeds the '35 fuel suppliedto it from the conduit 16 to the fuel supply housing 13 whence it isdelivered to the firing opening 12 on to fuel distributing meanscomprising a blast chamber 34 and a distributing plate 35. These fueldistributing means may be of any known construction and serve to scatterfuel over the fire by means of blasts of steam emitting from the jets ofthe blast chamber 34 associated with the fuel distributing plate 35.

The conveyer 15 has an operative connection (not shown) with a screwconveyer 18 mounted for rotation within the tender hopper 19 below thetender deck 20. The conveyer 18 in turn is operatively connected with apower device 21, located on the locomotive and this connection comprisesa telescopic shaft 22, universally connected at 23 with the power deviceand at 24 with a shaft 25. This shaft 25 is journaled upon the tenderhopper and has at its rear end a gear (not shown) which meshes with agear 26 (shown in dotted lines) secured to the rear end of the conveyer18.

With this arrangement of parts, fuel may be conveyed in a continuousstream from the tender hopper 19 through the conduit 14 into the fuelsupply housing 13, and thence on to the distributor plate 35 and intothe fire hose.

Coal for commercial use in fire boxes for locomotive boilers, steamboatboilers, and other large boilers, contains large lumps of coal and/orforeign matter. Such lumps, although able to move along hopper 19,cannot pass readily through conduits 16 and 14 of a stoker mechanismsuch as shown in Figure l. Oftentimes, such lumps are either carriedinto and caughtin these con veying conduits 16 and 14 or in some otherway effectually stop the operation of the stoker. To overcome thisclogging caused by large lumps in the fuel, the practice is to providethe delivery end of the tender hopper 19 with a crushing device such as36 (shown in dotted lines in Figure 1) which coacts with the conveyingscrew 18 in the hopper to crush large lumps of fuel in the fuel movingto the conveyors 16 and 14.

But these crushing devices heretofore used in connection with thefeeding mechanism of a tender hopper are only partially successful inovercoming complete clogging caused by lumps collecting in conduits 16and 14 or otherwise stopping the fiow of fuel because the crushingdevice frequently causes clogging of the fuel at the crushing deviceitself. This clogging results in complete stoppage of the flow of fuelfrom the conveyer and tends to create such excessive pressures in thefeeding mechanism as to strain and/ or break the crushing device, theconveyer 18, the engine operating the conveyer and other parts of thestoker.

In the present invention, I have overcome such difficulties as the abovepointed out by providing at the delivery end of the tender hopper 19 apowerful and effective crushing device 36, the structure of which isarranged in the form of a plurality of crushing surfaces or planes 3'7,38, 39 and 40 within the hopper and partially encompassing the deliveryend of the conveyer 18.

The crushing device as shown in the present embodiment is preferablycast in a single piece and essentially comprises the aforementionedcrushing surfaces 37, 38, 39 and 40 which converge on the conveyer 18 toform in eifect a hood shaped structure flaring outwardly against thedirection of the advance of fuel in the tender hopper 19. The planesurfaces 37, 38, 39 and 40 thus converging on the conveyer l8 intersecta back supporting structure or wall 47 of the crusher device 36. Theintersection for the most part is as indicated at 52 circular and in asingle vertical plane. However, inasmuch as the surfaces 37, 38, 39 and40 are in four separate planes, they do not form, with the back wall4'7, a completely circular intersection which lies in a single plane. Tomake the intersection 52 circular, I provide additional planes 55 and 56between surfaces 37 and 38, and 39 and 40 respectively. As shown inFigure 3, the intersection 52 partially encircles the conveyer 18.

The crushing surfaces 38 and 39 are reenforced by ribs 45 and 46respectively, extending from the surfaces to the rear wall 47. Likewise,the crushing surface 3'? is re-enforced by ribs 48 and 49; the crushingsurface 39 is re-enforced at the top portion thereof by a rib 50; and,the crushing surface 40 is re-enforced by a rib 51. The wall 47 providesfurther support for the surfaces 37, 38, 39 and 40 at the intersection52.

This arrangement of the crushing surfaces of crushing device 36, in asingle casting and reenforced by suitable ribs, accomplishes many newand highly advantageous results, and provides a, crushing structurewhich is scientifically designed to withstand terrific pressures,- andwhich is durable and efficient in operation.

The planes are disposed at varying angles converging on the conveyer andthis angular dispoing crushing and feeding operation, and which issubstantially fool proof in operation, the possibility of clogging beingreduced to a minimum.

As shown in Figure 2, the conveyer 18 in moving fuel forward toward adelivery end 56 of the hopper 19 rotates in a counterclockwisedirection; and with this particular motion of 'the conveyer 18 there isa tendency for fuel moving toward the delivery end of the tender hopper19 to rotate around the conveyer in a counterclockwise direction and topile up higher in the left hand side of hopper 19 than on the right handside. Because of this tendency of the fuel to pile up or to be forcedover to the left hand side of the hopper 19 and for other reasons, Iposition the crushing surface 39, which for purposes of description 1shall call the upper crushing surface, in the left hand forward cornerof the hopper 19. As shown in Figures 2, 3 and 4, this upper crushingsurface 39 extends over the top of conveyer 19 and slopes forwardly,downwardly and laterally, converging toward conveyor 18 from a point 57at the side of the hopper 19. I find it advantageous to make plane 39relatively long and wide whereby fuel moving laterally with respect to,and away from the screw conveyer 18, is crushed or broken by contactwith the crushing surface 39.

I have further found it advantageous to position plane 39 in such a waythat it is substantially parallel to a portion 59 of the conveyer 18 asthe vane of the conveyer 18 moves into the position shown in Figure 2.This parallel arrangement between the conveyer portion 59 and thesurface 39 increases the efficiency of crushing device 36 by bringingabout a more direct crushing action between the surfaces 59 and 39.

Positioned on the opposite side of the conveyer 18 from the uppercrushing surface 39 is what I may term a side crushing surface 37positioned in a vertical plane projecting toward conveyer 18 from apoint 60 at the side of the hopper 19. This surface 37 serves to crushfuel moving axially with respect to the conveyer 18 as well as thatmoving perpendicularly away from the conveyer from the broom of thehopper 19.

As shown in Figures 2, 3, 4 and 5, the plane 39 does not extend tointersect with plane 3'7, and in the space left therebetween there isprovided the crushing surface 38 which, for purposes of description, Ishall term the outlet crushing surface. The surface 38 is relativelysmall in area, and has a short, relatively steep slope toward theconveyor 18. By thus positioning and forming the crushing surfaces 37,38 and 39 so that the top edges thereof form a notch 45 which lies aboveand slightly to the rear of the delivery opening 61, I limit theeffective crushing area disposed over the conveyer 18, and so accomplishmany new results. For example, the limited effective crushing area overthe delivery opening 61 of the conveyer 19 provides for the escape offuel upwardly in the event of clogging of the system, for when cloggingoccurs and the flow of fuel from the delivery opening 61 is slowed up orstopped, the fuel which continues to move toward the delivery openingunder the action of conveyer 18 escapes upwardly and past the plane 38.In this way excessive pressure is prevented from building up in thecrushing structure..

Completing the crushing surfaces around the conveyer 18, the fourthcrushing surface 40 is placed contiguous to the upper crushing surface39 in a vertical plane sloping forwardly and laterally toward theconveyer 18.

I further increase the efliciency and capacity 7 of my crushing device36 by providing the planes of the crusher 36 to 40 inclusive with aplurality of teeth or projections as 41 extending therefrom at varyingangles to the planes. The teeth 41 provided on the various planes makethe planes effective to crush fuel which is not only movingperpendicular to the plates, but also that which may be moving laterallywith respect to the planes and in contact therewith.

From the above description of my crushing device 36, it is clear thatwith it I accomplish many new and highly advantageous results. Fuelmoving from the tender floor 20 into the hopper 19 is conveyed to thedelivery end of the tender hop per 19 by means of conveyer 18. Fuelwhich is small enough to lie within the vane of conveyer 18 is carriedon through the delivery opening without necessarily contacting with anypart of the crushing device 36. But, lumps which are too large to liewithin the periphery of the vane of the conveyer 18 are pushed upwardlyfrom the conveyer 18 in the direction of the upper plane 39 andsidewardly to the plane 37, where they are effectually crushed to suchsizes as may pass through the .delivery opening of the conveyer 18.However, if for one reason or another the fuel becomes clogged in thedelivery opening, or for some other reason, is not able to pass throughthe delivery opening, fuel continuing-to move forward toward thedelivery opening under the action of conveyer 18, tends to pack withinthe bounds of the crushing structure and excessive pressures immediatelybegin to build up. But, with my novel construction, whenever such aclogging occurs, the fuel coming from the rear of the hopper 19 escapesup the short small outlet plane 38. In other words, the moment fuelceases to flow from the delivery opening 61, even though the conveyer 18continues to operate, the fuel boils upwardly past the outlet plane 38,and thus terrific pressures which were heretofore caused by such aclogging are offset.

From the foregoing it is evident that my crushing device greatlyimproves flow of fuel from the floor 20 of the tender to the fire box,or back-head 10. Thus in the operation of this stoker mechanism the coalpasses through the deck 20 of the tender into the trough of the tenderhopper 19 and is moved therein by means of the conveyer 18, into thecrushing device 36 wherein the abnormally large lumps of fuel arecracked and broken up to normal size without any tendency to pack andcreate excessive pressures, and before discharge from the tender hopper.The fuel is then delivered to the transfer conveyer 15 by which it istransported and delivered into the ascending conduit formed by thehousing extension 14 and the lower portion of the housing 13. From thehousing '19 it flows to the blast chamber 34, from whence it isdistributed over the fire bed.

Another feature of my invention, and as shown most clearly in Figures 4and 5, is the increased pitch in the conveyer 18 in the vicinity of thecrushing structure 36. By thus increasing the accelerate the flow offuel through the hopper at this point, and in this way materially reducethe possibility of any clogging in the region of the crushing surfacesand in the region of the delivery end.

It will thus be seen that there is provided a construction of anessentially practical nature in which the several objects of theinventQn 'are attained.

While I have shown and described a particular construction embodying thenovel features of the invention, it is to be understood that the same isfor illustration only and it will be obvious that the construction andarrangement of parts may be variously modified and altered withoutdeparting from the spirit and scope of the invention as set forth in theappended claims.

I claim:

1. In a fuel crushing and feeding mechanism, a hopper, a screw conveyerlocated in the said hopper, a crushing structure associated with said.hopper and having a passage therethrough with slope forwardly andtowards said conveyer to forma fuel relief passage, the top edges of thethree surfaces forming a notch located above and slightly to the rear ofthe discharge opening whereby the flow of fuel up past said thirdsurface prevents excessive pressure.

2. In a fuel crushing and feeding mechanism, a hopper, a screw conveyerlocated in the said hopper, a crushingstructure associated with saidhopper and having a passage therethrough with a discharge opening, saidcrushing structure including an upper crushing surface slantingforwardly, downwardly and laterally toward said conveyer, asubstantially vertical side crushing surface on the opposite side of theconveyer from said upper surface and slanting forwardly toward saidconveyer, and a third crushing surface disposedabove said conveyer andbetween said upper and side surfaces and having a relatively steep slopeforwardly and toward said conveyor to form a fuel relief passage, thetop edges of the three surfaces forming a notch located above andslightly to the rear of the discharge opening whereby the flow of fuelup past said third surface prevents excessive fuel pressure fromoccurring during crushing operation; and the pitch of said screwconveyer increasing within the confines of the crushing structurewhereby the flow of fuel is proportionately accelerated in the confinesof said crushing structure.

3. In a fuel crushing and feeding mechanism,

- a hopper, a screw conveyer located in said hopper,

and between said upper and side surfaces, having a relatively steepslopeforwardly toward said conveyer to form a fuel relief passage, thetop rear edges of the three surfaces forming a notch located above andslightly to the rear of the discharge opening whereby the flow of fuelup past said surface prevents excessive fuel pressure during thecrushing operation.

4. In a fuel crushing and feeding mechanism, a hopper, a screw conveyerlocated in said hopper, a crushing structure associated with said hopperand having a passage therethrough with a discharge opening, saidcrushing structure including a plurality of crushing surfaces locatedabove said discharge opening and conveyer and other crushing surfaceslocated on either side of said conveyer and discharge opening, and saidsurfaces converging on said conveyer and discharge opening and forming acrushing zone encompassing the sides and top of that portion of saidconeveyer located within said crushing zone; the uppermost rear edges ofthe overlying crushing surfaces together with the uppermost rear edgesof side surfaces on one side of said conveyer forming a notch having itsapex located above and slightly to the rear of said discharge opening,said notch forming a top edge of a generally V-shaped fuel reliefpassage formed by said crushing surfaces and extending upwardly fromsaid discharge opening, said fuel relief passage serving as an outletwhereby excess fuel supplied to said crushing zone may pass out of saidcrushing zone.

WILLIAM THOMPSON HANNA.

